page 13 of the revo manual wrote:Patterns can also be played in reverse or backwards. If the unit is stopped and you wish to play a pattern backwards, hold the Shift/Clear key and then press the Play key. The pattern will now be playing backwards. To stop the sequencer, press the Play key.While a pattern is playing you can change its direction to play forward or backwards by using the same technique as above. Hold the Shift/Clear key and then press the Play key. When the loop point for the pattern currently playing is reached, the sequencer will change the playback direction.